Question

4. x/x+15=4/9, then x=
a) (-6)b) 6 c)12 d) 14​

Answer 1

» Given Question:

If $\bf { \dfrac{x}{x + 15} = \dfrac{4}{9} }$, then x =?.

» Required Solution:

Here, this is linear equation question.We can solve it using cross multiplication method.

$\bf { \dfrac{x}{x + 15} = \dfrac{4}{9} }$

$\:$

$\bf { \leadsto x(9) = 4(x + 15)}$

$\:$

$\bf {\leadsto 9x = 4x + 60}$

$\:$

$\bf { \leadsto 60 = 9x - 4x}$

$\:$

$\bf { \leadsto 60 = 5x}$

$\:$

$\bf { \leadsto x =\cancel {\dfrac{60}{ 5} } }$

$\:$

$\bf { \leadsto x= 12 }$

Thus, the value of x is 12.

$\boxed { \large \bf { Option \: C!! \: (12) } }$

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Verification:

$\red \bigstar$$\bf { \dfrac{x}{x + 15} = \dfrac{4}{9} }$

$\:$

Substituting values-

$\bf { \dfrac{12}{12+ 15} = \dfrac{4}{9} }$

$\:$

$\bf { \dfrac{12}{27} = \dfrac{4}{9} }$

$\:$

$\bf { \dfrac{4}{9} = \dfrac{4}{9} }$

$\:$

Thus, solved!!

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